more oled features and system freeze fixes

lib/oledProtection.js

@@ -1,6 +1,7 @@
 import GLib from 'gi://GLib';
 import Meta from 'gi://Meta';
 import Clutter from 'gi://Clutter';
+import Graphene from 'gi://Graphene';
 import * as Main from 'resource:///org/gnome/shell/ui/main.js';
 
 import {SettingsKey} from './settingsKeys.js';
@@ -13,6 +14,11 @@ const SHIFT_PATTERN = [
 
 const FORCE_ROTATION_CHECK_SECONDS = 60;
 
+// Extra margin, in pixels, added on top of the configured shift amount when
+// overscanning background actors — rounding/timing slack so a step never
+// exposes a sliver of empty stage at the trailing edge.
+const OVERSCAN_SAFETY_PX = 2;
+
 /**
  * Reduces OLED burn-in risk through three independent techniques:
  *  - pixel shifting: nudges the background actors a few px on a slow cycle
@@ -105,6 +111,7 @@ export class OledProtectionManager {
         const [dx, dy] = SHIFT_PATTERN[this._shiftStep];
 
         for (const actor of this._backgroundActors()) {
+            this._ensureOverscan(actor, amount);
             actor.ease({
                 translation_x: dx * amount,
                 translation_y: dy * amount,
@@ -114,12 +121,36 @@ export class OledProtectionManager {
         }
     }
 
+    /**
+     * Background actors (the real desktop background, and our own live
+     * wallpaper actor in most display modes) are sized to exactly cover
+     * the stage with no slack, so nudging one by a few pixels for burn-in
+     * protection would drag its edge inward and expose bare stage on the
+     * side it moved away from. Scaling the actor up slightly around its
+     * center — by just enough margin to cover the configured shift amount
+     * — keeps every edge overscanned past the stage bounds no matter which
+     * step of the shift pattern is active.
+     */
+    _ensureOverscan(actor, amount) {
+        const width = actor.width;
+        const height = actor.height;
+        if (width <= 0 || height <= 0)
+            return;
+
+        const margin = amount + OVERSCAN_SAFETY_PX;
+        actor.pivot_point = new Graphene.Point({x: 0.5, y: 0.5});
+        actor.scale_x = 1 + (2 * margin) / width;
+        actor.scale_y = 1 + (2 * margin) / height;
+    }
+
     _resetShift() {
         this._shiftStep = 0;
         for (const actor of this._backgroundActors()) {
             actor.ease({
                 translation_x: 0,
                 translation_y: 0,
+                scale_x: 1,
+                scale_y: 1,
                 duration: 500,
                 mode: Clutter.AnimationMode.EASE_OUT_QUAD,
             });